The present invention relates to a mercury switch and more particularly to a mercury switch wherein the switch housing/baffle member serves as one electrode with a second electrode suitably insulated from the housing being partially inserted into an open end of the housing.
Mercury switches are widely used to control pumps, solenoids, relays, alarms, etc. In particular, they are often used in conjunction with a float housing for detecting predetermined high or low liquid levels in sewage and drainage applications so as to activate a pump as required.
Among the many problems which must be overcome in mercury switch design is damage due to electrical arcing and contamination of the mercury supply.
The electrical arcing which occurs when an electrical circuit is made between the housing and the electrode positioned therein erodes the insulator insulating the electrode from the housing. In addition, the electrical arcing causes contamination of the mercury due to carbon and other material leaching out of the housing walls and other parts of the switch.
In addition, there are often problems with the switch reliably switching off and/or on at a particular angle of inclination. Sometimes there will not be a clean break or contact made and the switch will intermittently switch on and off for a period of time. Furthermore, the electrical arcing and corresponding heat generated thereby takes its toll on the electrode positioned in the housing and the other parts of the housing. After extended use, burnout of the electrode and/or the housing will frequently occur.
In Ser. No. 595,422, filed Mar. 30, 1984, a mercury switch solving these and many other problems associated with the prior art was disclosed.
The present invention provides a further improvement in performance over this switch.